my grandfather developed the payroll system on apple 2e's for the family business. I believe it was coded in basic. My grandfather passed away last February and there is one line of code that needs to be changed. It's just a variable that needs to be changed
What is the basic list of commands to do this? I have loaded the program into memory and then used new and rewrote the line of code and then saved the program under the previous name.

Your description suggests you destroyed the old program accidentally - I hope you have a backup. The "new" after loading would discard all existing program lines, the subsequent saving under previous name would only save the single line you entered as "the new complete program" overwriting probably hundreds of lines of BASIC code stored previously under that name.

Normally under BASIC typing a line number followed by Basic commands would just replace that line number. Proper procedure is: load old program. Find line number of line to be changed, e.g. with LIST. Then type line number followed by modified instructions. That will just replace 1 line with rest of program unchanged. Then save this program to disk again.